Ductile Iron Elbow — Standard 90° Cast Pipe Fitting

By Nico Yin · Qingdao Zhaoyuqi Machinery Co., Ltd.

Overview

The 90° elbow is the most widely used direction-change fitting in piping: a quarter-turn bend that connects two runs of pipe at a right angle. This page covers our standard-pattern ductile iron elbow in threaded and flanged ends, cast in-house by sand molding and machined to gauge. Ductile iron to ASTM A536-84(2019) gives the fitting a tensile strength of typically 65,000 psi minimum with useful elongation — a significant upgrade over gray cast iron for fittings that see installation torque, vibration, and water hammer.

As a casting factory, we supply this workhorse fitting to distributors, OEM equipment builders, and water-works contractors who need dependable volume supply rather than one-off specials. Typical applications include fire protection mains, irrigation networks, industrial water and air lines, and general plant plumbing. Because the pattern inventory is broad, common sizes ship quickly; special thread standards, coatings, and end styles are configured per order. The standard range covers 1/2" through 12" with 300 PSI WOG pressure class for threaded sizes.

Specifications

Customization & Sampling

Even a standard elbow offers meaningful options: BSP vs NPT, male "street" ends, flanged ends with custom drilling, extended legs, and grooved ends. The sampling process is requirement review → pattern selection or adaptation → first-article casting → gauge and dimensional report → customer approval → serial production. Samples of catalog sizes are typically available in 2–3 weeks; adapted patterns take 3–5 weeks. Cast-in logos and carton private-labeling are available for distributor programs.

Quality Inspection & Packaging

Every melt is analyzed on an optical emission spectrometer against the A536 chemistry specification, with tensile and elongation confirmed on test bars cast from the same heat. Product-level QC includes thread gauging (GO/NO-GO), center-to-face and squareness checks, wall-thickness sampling at the heel, and visual defect screening; hydrostatic or pneumatic testing is offered per order. Coated parts are bagged and packed in export plywood cases or on pallets, sized-mixed containers allowed. Our quality management system conforms to ISO 9001:2015 requirements.

FAQ

Q1: What is the difference between your ductile iron elbow and a gray iron one?

Ductile iron to ASTM A536 has nodular graphite, giving typically 2× the tensile strength and real elongation versus gray iron. In practice that means fewer cracked fittings during installation and better survival under water hammer and freeze-thaw movement.

Q2: Can I order mixed sizes in one container?

Yes — mixed-size, mixed-coating containers are standard for our distributor customers. Cartons can be labeled to your SKU system so the goods cross-dock directly into your warehouse.

Q3: Do you supply 150 lb equivalents or only 300 PSI?

Threaded ductile iron elbows in this range are commonly rated 300 PSI WOG; flanged Class 125 covers the standard 150 lb drilling. If you need another class, send the standard and we will confirm the wall design.

Related Products

• 45° Street Elbow

• 90° Reducing Elbow

• Reducing Tee

• Coupling

• Threaded Union

Get a Quote

For standard elbows, WhatsApp usWhatsApp us at +86 185 6156 7088 a simple size list, thread standard, and coating — we answer most inquiries with a full quotation within one working day, including FOB/CIF options and production lead time. For first-time customers we are happy to ship a mixed sample carton so you can check thread fit, coating quality, and casting finish before the first bulk order.

Need a formal quotation? Send your Ductile Iron Elbow drawing, quantity and target price through our quotation request form — it goes straight to the foundry inbox, and we reply with a priced offer, material certificate draft and production lead time within one business day.